This invention relates to power jointers, and, more particularly, to a clamping apparatus adapted to be mounted to a power jointer for making a smooth, finish cut on an end edge of a board.
One of the most difficult problems in woodworking is to obtain closely fitting joints between the mating edges of pieces of wood. Whether the pieces of wood are connected square to one another, or at angles such as 45.degree. or 221/2.degree., even the slightest variation between the mating surfaces can produce a poor joint. This is a particular problem in the fabrication of frames, cabinets, tables and other items where the joints are especially noticeable.
In the construction of rectangular or square picture frames, for example, a miter box is commonly used to obtain the 45.degree. cuts on the mating edges of the boards forming the frame sections. As is well known, a miter box generally includes a frame having a bed and back plate connected together in an L-shape, and a carriage adapted to support a saw which is positionable relative to the bed at various angles. Although in some circumstances a miter box can produce reasonably accurate 45.degree. cuts, it has several disadvantages. For instance, if the boards to be cut are quite long, it is difficult to support the board within the bed of the miter box and against its back plate while making the cut. Movement of the board relative to the bed or back plate during the cut results in an uneven edge. In addition, even though the saws of miter boxes usually have relatively fine teeth, the cut edges it produces are often rough and must be made smoother with sandpaper or a block plane.
Another problem with making angled or straight cuts along the edge of a board with a miter box or similar tool is that it is difficult to correct a cut which is uneven or which has been made at an incorrect angle. It is extremely difficult to cut a very thin sliver or section of wood from the edge of a board with a miter box to correct a poor cut. It is also difficult, and time consuming, to attempt to straighten a poor cut using a block plane, sandpaper, or similar means.
Power jointers and other types of power planar tools are frequently used to smooth edges of boards which have been rough cut, particularly the long or side edges of boards used for finish work, e.g., door and window frames in a house or other building. Power jointers have not been useful in cutting the end edges of boards, particularly at angles such as 45.degree., because of the difficulty in holding a board on end against the bed of the jointer and then moving the board over the cutting blade of the jointer without tipping the edge with respect to the bed and cutting blade.